PCI express (PCIe) is a high-speed serial computer expansion bus standard designed to couple for example periphery devices with a chipset of a main processor (e.g. CDU). The PCI express electrical interface is also used in a variety of other standardized interfaces, for example in ExpressCard which is a laptop expansion card interface and in SATA Express which is a computer storage interface. PCI express essentially defines separate serial point-to-point connections. Separate endpoints may be coupled via switches. This enables an establishment of direct couplings between PCI express devices.
Applications running at higher layers on top of PCI express, for example applications related to a peripheral device, may use various data unit sizes, for example various frame sizes or various packet sizes. Conventional implementations of PCI express and point devices read an exact amount of data available over a bus. Such data units may be not aligned with double words (DWORDS) used in PCI data transfer. In some cases, this may lead to performance losses.